Hard head, going the extra mile and doing a good job as usual. Impressed by your very thorough enclosure build/improvement thread a while back.
Overdrive, one problem with the stock flap is water can wick under flap and into muffler output even with flap intact, this is especially true if snow or ice sits on top of generator. That is why a raised pipe, either turned down or with flapper, is a better solution. If you look at the picture I put in this thread, you'll notice the original flap in still there. But my 802 came from a large batch in MD that sat around with the DMRO or GL lot with snow on them for months, and a lot of the guys on this forum that got them from same batch had water in mufflers, and some had water in the motor itself. I was fortunate enoght to get one with little water in it, but learned from others' experiences here.
Flappers are a good solution, but have never owned one that did not start rattling at some point or another (tractors, chipper etc.), hence my preference for a turn down.